In 3GPP (Third Generation Partnership Project), it is designed to enhance LTE (Long Term Evolution) systems and LTE-Advanced systems. Presently, it is discussed to introduce uplink carrier aggregation (UL CA) where the carrier aggregation technique is applied to uplink communication. In the uplink carrier aggregation, user equipment (UE) uses multiple component carriers (CCs) simultaneously to transmit uplink signals to a base station (evolved NodeB: eNB).